MAGNITUDE AND RATE OF CLIMATE CHANGESGuest post by Dr. Don J. Easterbrook, Dept. of Geology, Western Washington UniversityThe GISP2 Greenland ice core has proven to be a great source of climatic data from the geologic past. Ancient temperatures can be measured using oxygen isotopes in the ice and ages can be determined from annual dust accumulation layers in the ice. The oxygen isotope ratios of thousands of ice core samples were measured by Minze Stuiver and Peter Grootes at the University of Washington (1993, 1999) and these data have become a world standard.The ratio of 18O to 16O depends on...